This invention relates to a curtain operating assembly that has a track in which a sliding carriage is placed to which the curtain is fastened. The track also has a pulling band that moves the carriages. The assembly is equipped further with an electric motor, which has a cogwheel attached that engages the pulling band, and a clutch mechanism that allows movement of the curtain by hand.
Such a curtain operating assembly, or curtain suspension assembly, is generally known and is predominantly used in up-scaled residences, in office buildings and hotels. Such an assembly is user-friendly since the curtain can be moved by using a pushbutton. A clutch assembly makes manual movement of the curtain possible in addition to the movement by electric motor. Manual operation is necessary especially when curtains are used in office buildings or hotels. It is not apparent for the user in these areas that the curtain is operated by a pushbutton in conjunction with an electric motor and not manually. The uninformed user might therefore try to slide the curtain by hand. However, since the curtain is directly connected to the pulling mechanism of the electric drive, it is blocked and may not be moved by hand. There is the danger that the curtain, the pulling mechanism or parts of the drive mechanism may be damaged, according to the invention. The above-mentioned clutch mechanism makes it possible to move the curtain manually. The ability to move the curtain by hand is absolutely necessary if the curtain has to be moved in an escape route.
An assembly of this type is disclosed in EP-A-0 282 970. In this assembly, the drive mechanism is equipped with a planetary gear that disengages the electric motor from the pulling band and thereby the curtain may be moved freely by hand, if necessary. The disconnecting is accomplished by a brief counter-directional turn of the drive axle of the electric motor. The planetary gear assembly needs a relatively large space and is in many cases difficult to install.
An assembly of the same type is disclosed in EP-A-0 782 833, which also has an electric drive mechanism and which further allows manual movement of the curtain. A carriage is connected through a disengaged clutch mechanism to the drive band to be able to move the curtain manually. The clutch may be disengaged by a powered mechanism located above the curtain area. The clutch is disengaged automatically whenever the electric motor is switched on. The engagement of the clutch is caused by a stud that makes connection with a hole in the drive band. The clutch can tolerate only a relatively low drive force and is therefore not suited for very heavy curtains.